Sergeant Major Majszak is a native of Chicago, Illinois, and enlisted in the Marine Corps in August 2004. After completing recruit training at Marine Corps Recruit Depot San Diego and the School of Infantry at Camp Pendleton, California, he earned the MOS of 0311 Infantry Rifleman.
He reported to Echo Company, 2nd Battalion, 1st Marines in 2005, serving as a rifleman, team leader, and squad leader. During this tour, he deployed with the 13th Marine Expeditionary Unit, 31st Marine Expeditionary Unit, and a Military Transition Team to Iraq. He later served as the Chief Marine Combat Water Survival Instructor with 1st Marine Regiment, where he was promoted to Sergeant.
In 2010, Sergeant Major Majszak was assigned to Recruiting Station Chicago, serving as a canvassing recruiter and Staff Noncommissioned Officer-in-Charge. In 2014, he joined 2nd Battalion, 6th Marines, deploying with the 26th Marine Expeditionary Unit and subsequently serving with Golf Company after his promotion to Staff Sergeant
From 2017 to 2020, he served at School of Infantry-East as a Combat Instructor, Team Lead, Platoon Commander, Company Gunnery Sergeant, and Chief Combat Instructor, during which he was promoted to the rank of Gunnery Sergeant.
In September 2020, Sergeant Major Majszak reported to 2nd Battalion, 1st Marines and deployed with the Special Purpose Marine Air-Ground Task Force in support of Operation Allies Refuge in Kabul, Afghanistan.
In June 2023 Sergeant Major Majszak was promoted and reported to India Company 3rd Battalion 25th Marines in Johnson City, Tn as the Inspector Instructor Company First Sergeant.
In May 2026, he was promoted to his current rank and reported for duty as 3d Battalion, 4th Marines Sergeant Major.
Sergeant Major Majszak personal decorations include the Navy and Marine Corps Commendation Medal with Combat C (4), and Navy and Marine Corps Achievement Medal (2), and Combat Action Ribbon (2).